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The Bus Speed Guide


Well, so much for the importance of the bus speed in the real world!! Hope everyone has gotten the message.

These results should change a lot of preconceptions regarding system performance.

The Bus speed of 83 MHz , achievable for the first time on the Asus P/I-P55T2P4 rev. 3 , is the hottest and most powerful tool to increase your system performance (for the cost of a motherboard) to so far unknown heights.Don't worry too much about your RAM at 83 MHz bus speed. My EDO RAM is running just fine at 83 MHz and I am not using slow timing settings at all. SDRAM may be the RAM of the future, but at present, we want to run our systems fast and cheap. EDO RAM is just fine for that. The claims by Intel and the RAM industry that all bus speeds above 66 MHz require SDRAM have just been refuted.The only touchy factor of the 75 or 83 MHz bus speed are the PCI devices. As you know, they are running at half the bus speed, which means, that they are running faster than the allowed 33 MHz. Some video and SCSI controller cards don't like that at all. Most do though. To find out, which PCI devices are able to cope with higher PCI speeds, have a look at my 75/83 MHz Bus Speed Survey .CPU clock speed is secondary , there's no point to just overclock to some amazingly high CPU clock speed, without considering the Bus speed.The higher the Bus Speed you can achieve, the higher is the system's performance'Less' often means 'more'! Don't forget, that a small or even no increase in CPU clock speed together with a high bus speed might be your fastest setting.The Pentium 150 is NOT a useless CPU at all , it's just wonderful as a P150 at 2 x 75 MHz or as slightly overclocked P166 at 2 x 83. I my eyes, this CPU has to be considered the BEST BANG FOR THE BUCK !!!The Pentium 200 is only really great at 208, 225 or 250 MHz . Otherwise it's outperformed by a P166/83 or a P188/75.An increase of the bus speed often makes far more difference than an increase of the multiplier . In Quake, changing from x1.5 to x2 multiplier gives you an increase of 18% (e.g. P100 to P133), changing from x2 to x2.5 makes only 8.1% difference, changing from x2.5 to x3 only gives you an increase of not more than 6.7% (e.g. P166 to P200). It's even worse in Winstone. This actually also shows that going from 208 MHz to 250 MHz results in a performance gain of puny 6%. Consider this before you go out and buy a new CPU or before you try to fry your current CPU with overclocking!Increase of multiplierPerformance Gainfrom x1.5 to x218.0%from x1.5 to x2.527.5%from x1.5 to x335.9%from x2 to x2.58.1%from x2 to x315.2%from x2.5 to x36.6%